Add "arch_test" gtest for assembly stub constants, add some ARM64 assembly code

Add a test that (1) checks all callee-save method frame sizes for
all architectures, (2) checks thread offsets for the runtime
architecture and (3) checks callee-save method offsets for the
runtime architecture.

The "asm_support_XXX.h" files now only contain definitions that are
common between all architectures. Architecture-specific definitions
(i.e., special registers names) have been pushed into the corresponding
.S file. This change was required to be able to undefine definitions
in the test, so that multiple tests can be written in one file.

Test (1) above is in a sense two-stage. The arch_test gtest compares
constants (if it finds them) against the frame size as reported by
the ArtMethods created by the Runtime. This works for all architectures
as we can provide the instruction-set to CreateCalleeSaveMethod. The
second stage of the "test" are preprocessor tests with "#error" in the
case that the constants are not the expected value.

Optimally I'd like to change that to an actual runtime test exercising
the assembly code, which would also allow to check whether the right
registers are stored.

Also added missing assembly code for ARM64 for the callee-save macros.

Also fix X86_64 compilation for Clang 3.5.

Change-Id: I018e6433dffd3d31ba3bfcd75661653f4c7b6552